Improper usage of lithium-ion batteries can result in irreversible harm to their positive and negative electrodes. The positive electrode is adversely affected by excessive discharge, leading to the collapse of its carbon sheet structure. Consequently, this collapse impedes the insertion of lithium ions during subsequent charging cycles. On the other hand, overcharging causes an excessive influx of lithium ions into the negative carbon structure. Consequently, some of these ions become unable to be released anymore, further aggravating the damage caused.
To calculate the charging capacity of a battery, one must multiply the charging current by the time it takes to charge. It's important to note that when the charging control voltage is constant, a higher charging current will result in a faster charging speed but a smaller charging power. In order to avoid reducing battery capacity, it's essential to avoid excessive charging speed and inappropriate termination voltage control. Insufficient battery capacity can occur in cases where not all of the active material of the electrode is fully charged due to an improper charging termination voltage control point. This deficiency in charging quality increases as the number of cycles goes up.